How to fix inability to open notebook from web in MS-OneNote

A lot of people seem to experience this problem, where the menu item “Open in OneNote” in the OneNote webapp results in the error: “To open this notebook your computer must be running a supported version of Microsoft OneNote and a browser that supports opening files directly from the Office Web Apps.”

Here is what seems to have solved it for me (it only started to work when owssupp.dll was reinstalled. However, some of the earlier steps may also be necessary, notably adding to the “trusted sites”).

To open from OneNote desktop, as opposed to form the webapp, I tried to find out the URL of OneNote notebook

Easiest way is subtracting the edit.aspx portion from the OneNote webapp URL you are viewing.

Or if you can open the notebook on a different computer in OneNote, right-click on the notebook in the left tree and choose properties, or hover over one of its section headers above it to read the tooltip).

Then in OneNote on the offending computer, menu:file/open/ instead of browsing, paste the URL. This failed without providing any feedback:

Then I tried following the tips under the link “troubleshooting” in the error message.

Here is wishing that this were easier.., but now I can also open from OneNote / File / Open, and give the URL on live.net (giving the URL does not open directly, I have to press open again to open the OpenNotebook.onetoc2):